Migration steps:

• tsconfig.json

  • compilerOptions.module should be set to node12 or nodenext (to enable top-level async/await)

• package.json

  • All packages need to have type set to module
  • All packages should declare a correct exports property
  • All dependencies should be updated to their esm variants (with some caveats)

• ts files

  • All relative imports should have file extensions (.js)
  • all require statements should be removed in favor of import() or require via createRequire

Reference documentation:

• https://2ality.com/2021/06/typescript-esm-nodejs.html
• https://devblogs.microsoft.com/typescript/announcing-typescript-4-7-beta/#ecmascript-module-support-in-node-js

Reference issues:

• Migrate to native ESM #1035
• checkup-plugin-ember is incompatible with ember-template-lint 4.0 & eslint v8 #1158